It seems like one of the major reasons people don't like to workout is the amount of time it takes to do so. However, a new study in the Journal of Physiology suggests you might be able to get all the exercise you need in just 20 minutes if you're willing to work at it.

We've talked briefly about interval training before, but this is one of the first studies to dig into if it actually works as a replacement for the usual recommendation of 30 minutes of continuous exercise. The idea is simple. You workout for one minute with strenuous activity and push your heart rate to about 90 percent of its maximum rate. You can get a rough estimate of your maximum heart rate by subtracting your age from 220. After the minute is up, you slow down and recover for one minute. You then repeat this 10 times for a total of 20 minutes (or 10 minutes of actual exercise). You can use this for running, cycling, swimming, or any number of cardiovascular workouts. (Note that this isn't exactly the same as traditional high-intensity interval training, in which you push to 100 percent of your maximum heart rate.)